Add operator|=(result&, value)

test/result_or_eq_value.cpp

@@ -0,0 +1,102 @@
+// Copyright 2017, 2021-2024 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+using namespace boost::system;
+
+struct X
+{
+    int v_;
+};
+
+struct Y
+{
+    int v_;
+
+    explicit Y( int v ): v_( v ) {}
+    Y( X x ): v_( x.v_) {}
+
+    Y( Y const& ) = delete;
+    Y& operator=( Y const& ) = delete;
+
+    Y( Y&& r ): v_( r.v_ )
+    {
+        r.v_ = 0;
+    }
+
+    Y& operator=( Y&& r )
+    {
+        if( &r != this )
+        {
+            v_ = r.v_;
+            r.v_ = 0;
+        }
+
+        return *this;
+    }
+};
+
+struct E
+{
+};
+
+int main()
+{
+    {
+        result<int> r( 1 );
+
+        r |= 2;
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( *r, 1 );
+    }
+
+    {
+        result<int, E> r( in_place_error );
+
+        r |= 2;
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( *r, 2 );
+    }
+
+    {
+        result<Y> r( in_place_value, 1 );
+
+        r |= X{2};
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( r->v_, 1 );
+    }
+
+    {
+        result<Y, E> r( in_place_error );
+
+        r |= X{2};
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( r->v_, 2 );
+    }
+
+    {
+        int x1 = 1;
+        int x2 = 2;
+
+        result<int&> r( x1 );
+
+        r |= x2;
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( &*r, &x1 );
+    }
+
+    {
+        int x2 = 2;
+
+        result<int&, E> r( in_place_error );
+
+        r |= x2;
+
+        BOOST_TEST( r.has_value() ) && BOOST_TEST_EQ( &*r, &x2 );
+    }
+
+    return boost::report_errors();
+}